OCD is a clinical syndrome consisting of obsessive thoughts or compulsive behaviors or both. Mainly, the patient is aware of the presence of compulsions or countercompulsions, so that when the compulsive thoughts and compulsive behaviors occur, the patient feels distressed and anxious. The patient is aware that the compulsive thinking or compulsive behavior is unnecessary or unreasonable, but the patient cannot get rid of it, so the patient is in great pain, which is a very important part of the painful experience of OCD. There are many clinical manifestations of OCD, including obsessive thoughts, obsessive exhaustion, obsessive associations, obsessive memories, obsessive intentions, and so on. Compulsive actions and behaviors may also occur, such as compulsive examination, compulsive washing, compulsive questioning, or seeking reassurance to satisfy their obsessive thoughts. Once the diagnosis of OCD is confirmed, psychotherapy and medication are needed. Psychotherapy is commonly used to prevent exposure and response, while medication is mainly 5-hydroxytryptamine reuptake inhibitors.